Explain any two reasons for differences in climates around the world

There are differences in climate around the world because of differing amounts of radiation received from the Sun at different parts of the Earth at different times of the year. More heat from the Sun is received near the equator than near the north and south poles where the angle of the Sun's rays is lower.

d. new methods of assembly are introduced.

explanation:

this allows for the goods to be made on a larger scale. not faster because now it is shown to be made better, hence the greater productivity in the question. it is calling for something new to be introduced.